<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>!逻辑运算符</title>
    //两次!!转换为boolean类型
    <script type="text/javascript">
        console.log(0,typeof (!!0),!!0);
        console.log(1,typeof (!!1),!!1);
        console.log('',typeof (!!''),!!'');
        console.log('asd',typeof (!!'asd'),!!'asd');
    </script>
</head>
<body>

</body>
</html>